Conventionally, various kinds of tape printers which can print on a print tape of a long printing medium, displaying a text composed of characters inputted with input means such as a keyboard, have been suggested. In the tape printer, the print tape is generally supplied from a tape cassette in which the print tape and an ink ribbon are wound on each spool and housed in a predetermined-shape cassette.
In a tape cassette housing part of the tape printer, there are provided a print head for printing on the print tape and a platen roller for feeding the tape. In printing, the print tape is pressed against the print head by the platen roller to be printed the text thereon, and discharged as a printed tape. Herein, in order that the tape cassette is removed and re-installed for replacement, the print head and the platen roller need to be moved away from a pressing position of the print tape in order to release pressure exerted on the print tape by the print head and the platen roller. Accordingly, at least one of the print head and the platen roller is made movable, and a release member is provided to move the print head or the platen roller between the pressing position and a withdrawing position. Further, a cassette cover for covering the tape cassette installed in the tape cassette housing part is also provided. In printing, the cassette cover is closed to prevent entry of something extraneous from outside.
Japanese Patent Application laid-open No. H10(1998)-100494 discloses, as the release member described above, an engagement member which is provided in the cover element for moving a holder member (the platen roller) to the pressing position when the cover element is closed, and an elastic member for moving the holder member (the platen roller) to the withdrawing position when the cassette cover is opened.
However, in the tape printer of the above publication, there is a risk that, while the tape printer is stored for a long period with the platen roller and the print head being in contact, the platen roller and the print head have adhered to each other because of the absolute contact between a front face of the head and a roller rubber, and they can be no longer returned to the withdrawing position with a force of repulsion. If the repulsion of the elastic member is enhanced to solve the problem, the holder member and the like need to be strengthened, which increases costs.